Conventionally, a mounting structure of a ceramic capacitor is disclosed in JP-A-H06-69625.
When the ceramic capacitor is directly soldered on a printed circuit board or an aluminum board, the ceramic capacitor may be broken by application of large thermal stress since a thermal expansion coefficient of the ceramic capacitor is largely different from the board. In view of this difficulty, in JP-A-H06-69625, as shown in FIG. 4, an opening 101 is formed in the flexible board 100. Further, the ceramic capacitor 110 is soldered on the board 100 so as to bridge the opening 101. The flexible board 100 is mounted on an aluminum board 120 or a printed wiring board.
As shown in FIGS. 5A and 5B, JP-A-H08-139437 teaches that a protection member 220 made of insulation material is mounted on a surface of a flexible board 200 so that an element soldered on the flexible board 200 is protected. The protection member 220 has, for example, a square frame shape, which surrounds a periphery of the element 210. The protection member 220 has appropriate rigidity. When the protection member 220 is mounted on the flexible board 200, rigidity of a part of the flexible board 200 covered with the protection member 220 increases. Thus, the flexible board 200 does not easily bend. Accordingly, as shown in FIG. 5B, when a roller 230 is displaced on the surface of the flexible board 200, the part of the flexible board 200 surrounded with the protection member 220 is prevented from bending. Thus, unnecessary peeling-off force is not applied to both sides 241, 242 of the part of the flexible board 200, on which the element 210 and a solder portion 240 are mounted. Accordingly, the element 210 and the solder portion 240 are protected.
However, in the mounting method described in JP-A-H06-69625, since it is necessary to mount the flexible board 100 on the aluminum board 120 or the printed circuit board, and the ceramic capacitor 110 is soldered on the flexible board 100. A cost for manufacturing the aluminum board 120 and the printed circuit board is additionally necessary. Further, the aluminum board 120 or the printed circuit board, on which the flexible board 100 is mounted, has dimensions larger than the flexible board 100. Accordingly, dimensions of a mounting structure for protecting the ceramic capacitor increases, and therefore, it is not suitable for mounting the ceramic capacitor 110.
In a technique described in JP-A-H08-139437, a cost for manufacturing the protection member 220 is additionally necessary. Further, since the protection member 220 surrounds the periphery of the element 210, which is mounted on the flexible board 200, it is necessary to avoid interference between the protection member 220 and other elements mounted on the board 200. Thus, it is difficult to secure a space for arranging the protection member 220.